Wire coiling tool



July 14, 1970 W. O. MUELLER WIRE COILING TOOL Filed Jan. 26, 1968 INVENTOR.

//M/r/ a Mg// United States Patent "cc 3,520,334 WIRE COILING TOOL William 0. Mueller, Detroit, Mich., assignor to Hans Sickinger Co., Pontiac, Mich., a corporation of Michigan Filed Jan. 26, 1968, Ser. No. 700,786 Int. Cl. B211? 3/02, 3/04, 45/00 US. Cl. 140-9234 Claims ABSTRACT OF THE DISCLOSURE A wire coiling tool for spiral wire binders comprising split hollow body halves each of which has a series of inwardly extending pins, the facing pin sets being offset by one-half the wire pitch.

BACKGROUND OF THE INVENTION Field of the invention The invention relates to spiral binder applying machines for notebooks or the like, and particularly to wire coiling tools therefor. In such machines, a group of perforated sheets with covers is supported in alignment with the tool, through which a wire is fed and formed into a spiral which is at the same time threaded through the holes in the stack of sheets. The wire, which is fabricated of steel but may be coated with a softer material such as brass or copper, is then severed at both ends of the spiral and crimped, the book being discharged and another stack of sheets placed in binding position.

Description of the prior art Wire coiling tools in such machines are conventionally fabricated as a tubular member with internal grooves corresponding to the wire pitch. A mandrel rotates within this tool and because of its shape frictionally drives the wire around the spiral groove in the hollow body, the spiral being fed out the open end of the body and threaded through the stacked sheets.

If the wire is coated as aforesaid, the friction between the wire and forming elements could create damage. to these elements or to the wire coating, and could also create harmful increases in the wire and tool temperatures, particularly when these parts are operated at high speed. Another disadvantage of the prior art type of coiling'tool body, which is exemplified by that shown in application Ser. No. 503,704, filed Oct. 23, 1965, by Claus Ostermeier, now Pat. No. 3,407,851, issued Oct. 29, 1968, is the fact that it is diflicult to initially feed the wire through the coiling tool preparatory to starting a machine. A third drawback of the conventional tool has been the unavoidable rubbing action created on the mandrel surface because of the capstan effect of its cone shape. While a highly polished mandrel would reduce this rubbing action, which creates nearly imperceptible marks on the finished coil, it has heretofore been impractical to provide such a polished mandrel because of the danger of occasional stoppage of the coiling process due to lack of willcient frictional transporting power.

SUMMARY OF THE INVENTION Briefly, the invention comprises a hollow body made up of two split halves, and a flared coil mandrel rotatably mounted therein. The inner ends of the body halves, are provided with flanges so that they may be firmly secured to a support. The body halves each carry a set of cylindrical pins, the facing pin sets being offset from each other by one-half the wire pitch. These pins, which have inner ends closely adjacent the mandrel surface, act as guides during the coiling process While imposing a minimum of frictional resistance on the wire. It is therefore possible to 3,520,334 Patented July 14, 1970 use a highly polished mandrel without danger of loss of driving power, since it is unnecessary to overcome the excessive friction inherent in the prior art type of tool.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view, parts being sectioned, of the wire coiling tool of this invention;

FIG. 2 is a top plan view of the tool taken in the direction of the arrow 2 of FIG. 1;

FIG. 3 is an end view of the tool taken in the direction of the arrow 3 of FIG. 2; and

FIG. 4 is a detailed view of the flared mandrel.

DESCRIPTION OF THE PREFERRED EMBODIMENT The wire coiling tool is generally indicated at 11, and is carried by a cylindrical coiling tool housing 12 which encloses a coiling shaft 13 rotatably mounted therein by bearings 14. A coiling mandrel 15 is detachably connected to shaft 13 and extends outwardly therefrom. The construction of this mandrel is seen in FIG. 4, the mandrel having a cylindrical attaching section 16 extending within hollow shaft 13, and a flared driving portion 17 which may be highly polished.

The driving section 17 is disposed within a forming body generally indicated at 18 and comprising two element halves, a front forming element 19 and a rear forming element 21. The elements are of elongated shape and fit together to form an elongated hollow body which is shaped somewhat like a cylinder but with top and bottom portions cut away by parallel planes. The elements have semicircular flanges 22 and 23 which are held against the face 24 of housing 12 by a nut 25 threadably mounted on the housing. Semicircular hubs 26 and 27 fit into a bore of housing 12 to maintain the radial position of elements 19 and 21.

Elements 19 and 21 carry sets of guide pins 28 and 29 respectively, these pins extending radially toward bight portion 17 of the mandrel from opposite sides. As seen in FIG. 2, the interior portions of elements 19 and 21 are removed to expose the inner portions of pins 28 and 29 to view. The pins of each set are in evenly spaced parallel relation, and are successively shorter in a direction toward the outer end of the mandrel. Furthermore, the end surfaces of pins 28 and 29 are shaped so as to be complementary to the flared and curved surface of the mandrel guide portion 17, and are closely adjacent the surface of the mandrel. Pin sets 28 comprises six pins in the illustrated embodiment whereas pin set 29 comprises seven pins. The pins comprising set 28 are shifted axially from the pin set 29 by distance equal to one-half the pitch of the coil of wire 31 which is to be formed, and the spacing in each pin set is equal to the pitch of the wire.

The portions 32 of elements 19 and 21 adjacent flanges 22 and 23 abut each other, and a tapered space 33 is formed in element 21 at the juncture of these abutting surfaces with the open portion of element 21. This opening 33 is to permit wire to be fed in at this point which is before the longest pin 29. Because of the open nature of the tool elements, the wire may then be manually threaded back and forth between adjacent pins 29 and 28 in the manner indicated. Another recessed portion 34 is formed at the outer end of element 19 to accommodate a wire cutting knife partially shown at 35, which operates close to the exit point of the wire at the end of the coil forming cycle. 7

A pair of locating pins 36 and 37 are fastened to the end surface of housing 12 and extend axially therefrom, fitting in notches 38 and 39 respectively in flange 23 of rear element 21. These pins will insure the proper mounting of elements 19 and 21 as far as their front and rear positions are concerned and will prevent accidental rotary shifting of the elements during a working cycle.

In operation, mandrel 15 will be rotated, thus frictionally driving the wire between the sets of pins 28 and 29 which serve to guide the wire so as to form a spiral which will be fed out at the right hand or exit end of the tool and threaded through the stacked sheets 36.

It will be noted that the frictional resistance created by pins 28 and 29 to the movement of the wire will be minimal since these pins will have only point contact with the wire. Thus, if the wire is coated with softer material such as brass or copper, the possibility of damage to the coating by means of friction or of harmful increases in the wire and tool temperatures will be minimized.

It will also be possible to use a highly polished mandrel surface 17 thus avoiding the creation of marks on the surface of the wire, because the minimal frictional resistance offered by pins 28 and 29 will permit such a highly polished mandrel to still have a capstan effect.

While it will be apparent that the preferred embodiment of the invention disclosed is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. A wire coiling tool for forming spiral wire binders comprising a rotating axially fixed mandrel, and a stationary body surrounding said mandrel and having a plurality of circumferentially spaced sets of inwardly extending cylindrical pins, the inner ends of which are closely adjacent said mandrel, said pin sets being in rows which extend axially with respect to said mandrel.

2. The combination according to claim 1, there being two oppositely facing pin sets offset by one-half the wire pitch.

3. The combination according to claim 2, said body comprising split halves each of which carries one of said pin sets.

4. The combination according to claim 3, said body halves each comprising a flange, a coiling tool housing,

and a nut threadably mounted on said housing and securing said flanges thereto.

5. The combination according to claim 4, said body halves having abutting surfaces adjacent said flanges and being spaced from each other outwardly of said abutting surfaces, whereby a wire to be formed into a spiral binder may initially be manually threaded back and forth between said pins.

6, The combination according to claim 3, said body halves together being generally cylindrically shaped but with opposite sides cut away to form parallel surfaces.

7. The combination according to claim 4, said body halves also having hubs fitting into a central bore in said coiling tool housing to insure proper radial location of the halves.

8, The combination according to claim 7, said coiling tool housing also having at least one pin extending axially therefrom, and a notch in the flange of one of said body halves for receiving said pin, where-by accidental rotary shifting of said halves during a working cycle will be prevented.

9. The combination according to claim 3, one of said body halves being further provided with a recessed portion adjacent the innermost pin for feeding a wire toward said P111.

10. The combination according to claim 3, further provided with a recessed portion at the exit end of one of said body halves for accommodating a cutting tool.

References Cited UNITED STATES PATENTS 3,101,750 8/1963 Pfaflle 923 FOREIGN PATENTS 329,747 6/1958 Switzerland. 469,005 7/ 1937 Great Britain.

CHARLES W. LANHAM, Primary Examiner E. M. COMBS, Assistant Examiner US. Cl. X.R. 14092.3 

